Measuring and actuating device



Jan. 18, 1955 Fi1ed sept. 16, 1950 R. E. A. ToRNKVlST ET AL MEASURING AND AcTUATNG DBvcE 4 sheetsSheet 2 Jan. 18, R. E. A. ToRNKVIST ETAL 2,699,757

MBASURING AND AcTUTNG DE:vcE=

4 sheetsSheet 3 Filed sept, 16 1950 Jan, 18, 1955 R. E. A. ToRNKvlsT ETAL 2,699,75

MEASURING AND AcTUATNG DEvcE 4 SheetsSheet 4 F1ed Se t. 16, 1950 .The eXact change of length Z is in thiS caSe the diSfance betWeen the extefiof end sufface of the cylindef end and the end Surface of the pToiecting piston TodShown iI1 bfoken 1ines. The adjustnlent of the meaSufe chango fof this type of hydfaulic unif iS eXtfenTely easy, fof lt Tequifes only a sn1oothing of the piSton Tod end. /lteT- natively the piston fod end can be f11fniShed vvith an ad justing Scfevv, pTovided vvith af end plate and can be locked in the desifed position aftef the adjuStn1ent- In this Inannef one oan fof inStance con1pensate changes in leI1gthca11Sed by vveafi11g. The cleafance of the piston vvithin the cylindef iS in this caSe unin1 oftant, pfovided it is lafgef than the specific diStance change A1thoUgh, i1 the descfiption of the en1bodiInentS of the invention in fhe foHOWing figureS the hydfaLIlic units are inustrated accofding to Fig- 1 it is evident thaf in aH caSeS hydraI11ic unitS accofding to Fig. 2 can be subStituted.

zccoTding to Figs- 3 and 4 the hydraulic unit is a dou ble eleInent conlposed of tvvo elenlents according fo Fig. 1. The cy1indef body has thuS tWo cyHnder chambeTS 10 and 11 With a oyHndof botfom 12, coInInon to both, cloSe to Which theTe is a ring-fofnled cavity 13, fespoc tively 14, to lead the oil, Tunning thfough the oil duct 15, feSpecfively 16, behind the piStons 17, feSpectively 18.

alferafions becanse in Telation to the fota1 distance alfera- L fion the diITlensions of the eleInent Wi11 be sInaller than if tvvo Separate disfance elefnents`vvould be 11sed.

Especia11y fof 1aTgef diStance alteTations, it is, how evef, of advantage to uSe hydfauHo unitS of piston-cy1- indeT type fixe(1fe1eScopical1y one vvithin another. 5, 6, and 7 Show as an example embodiments with two diStance eleInenfs fixed telescopicaHy in felation to each other. In this way the IniniInuIn diITlensions of the eleInent are vefy Sfrlall in relation to the high liInit vhich can be obtained- 1ccoTdfng to Fig. the diSfance elen1ent iS coInpoSed of an exteriof cy1indef vvith oi1 duct opening cloSe to the cy1indef botton1 behind the piston 21- This piston Figs.

21 haS itS part coTTesponding to the iston rod foTIned into a cylinder Which endoseS a piston 22 vvith a piSton fod 23, having an oi1 duct 24, Which is connected to the oi1 Supply by a connectioI1 piece 25 and conductS the oi1 behind the piSton 22 Which has a contfa1 1edge 26 With SIna11er dianTetef than the piSton, So that the oi1 iS conducted into the Ting-forIIled space betvveen the piSton in its innef poSition and the boffoIn of the cylinder 21.

T11e embodiment according to Fig. 6 diffefS from that i11ustrafed in Fig. 5 by the oil duct aTrangement of the in11er cylindef. A cyHndef 27 Wifh an oi1 duct 28 encloSeS a cylindeffoTIned piSton 20. T11iS enc1oses in ftlfn a piSton 30 vvith a piSfon T()d 31, vhoSc end proiecfS in the initial posifion of the elen1enf from cyHnder 20, .The oi1 iS conducted behind fhe piston 30 through a dL1cf 32 in the back of the piston cylinder. The duct 32 connecfS the inSide of the cylinder 20 With the Space between fhe cy1inde1 20 and the cy1inder 27. In itS Wan thefe iS a duct 32 which in ifs turn is connected to the oi1 pipe. In the fronf end of the cyHndef 27 iS a cifcular oil gToove 32 Fig. 7 Shows a doub1e e1ement coInposed of fwo fele Scopic elen1entS according to Fig, 6 aS i1lllstfafed in Fig- 3 In the above Inentioned en1bodinlentS the e1eInentS are also accufately adiuSted to the desired paftia1 of total e1eInent a1fefationS, Which are eXact and specific foT e efy elefIlenf. The paftia1diSfance alteTafionS occurring wlthin the Sanle hydrau1ic unif do not have to be equa1. A1though on1y fvvo felescopicany arfanged hydTaulic nits have been inustTated it iS evident that fhree of Severa1 eloInentS can be affanged in a SiInilar Inannef. ESpeciany thlS can be done in connection vvith thQ fQ1lQv embodi n1ent of the invention although fof the Sake of clafity the eXample is 1iInited to foUT elementS.

AS Fig. 8 shovvS, the hyaraulic Unit in itS il1itial fofn1 is a cylindef IneanS 33, Whose botfon1 paTt haS an innef diametef, Which is a 1ittle smanef than the diaInete1 of the oppoSite end, in ofdef fo foTn1 a Shou1def on Which a Inovable Slide 34 abutS vvhen puShed in. Betvveen fhe bottom of the cylindef IneanS 33 and the slide 34 there iS a n1eInbrane containef 35, to which an oi1 duct 36 conducts goi11g fhfongh the cyli11def Wall. such a hydfaulic unit iS pafticulafly S11itable iI1 oases of SIIla11 diStance altefations ovving fo fhe fact that the extension of the elenlenf i11 the expansion direcfion can be n1ade vefy SIIlall. The Inen1bfane containef can be 1ade in fflotaL but a Inen1bfane in the fofIn of a fLIbbef bag vvith inlef ToSpectively ounet fof the pfesSufe medium iS pTefeffed.

Fig, 9 ShovvS a felescopic unit of Ineolbfane fype. one hydfaulic unit 37 according to Fignre 8 iS entifely Inade a Inovable paft of a surfounding cylinder IneanS 38 With a IIlef1bfane 30. The cy1indef II1eanS 38 in ifs tuTn iS fixed to a suffounding cyHndef IneanS 40. In the fingfofIned Toon1 betWeen them thefe is a fingfofIned mem bfane confainef 41. The meanS 40 iS in ifS tufn suf Tounded by an extefiof n1eanS 42 With a Ting-fofIned Inen1bfane containef 43. The oi1 SUpply to the different hydfaulic I1I1itS vvithin each othef can be affanged, aS Inen tioned, thfough oil ductS in the bottom of the cylindeT fneans, vvhich oil ductS conduot to the fespective Inen1 bfanes.

Fig. 10 ShoWS a double element compoSed of two hy dfaU1ic units accofding fo Fig. 9

To avoid a 11exible feeding pipe, the D1eaSuring device Shovvn in Fig. 11 has no sepafate cy1indef, the parts of the diffefent elements being arranged in a common cy1- inde 44, Which at the Same fiIne is the Suppofting and glJiding IIleanS of the nleaSufing device. The elenenf pafts consiSt of a Inovable centra1 ring 45 with Hange caSingS 46, 47 nxed to ifs cenfof apeffure; theSe f1ange caSings afe attached by a ScfeW bolt 48. The lnovable paftS, coffeSponding fo the piStonS, are coInposed of tvvo annular pisfons 49 and 50 With a Stepped cfosS Section. The 1eff paft of the element iS formed by an element of the type accofding fo Fig, 1 and its fighf paft of the elefnent type accofding to Fig. 2. These elenentS can, of coufSe, be of the San1e type and can also be used sepaTately, though fhe design shows them aTTanged vvithin a double element. The oi1 Supply to the TeSpective element iS ef fected thfough feSpective ducfS 51 and 52, Which afe coInpafafively lafge in pfopoftion to the axia1 Inotion of the hydfan1ic uoit. In thiS vvay the connection to the annulaf fooInS 53 and 54 being befvveen the annulaT pistons and the cyliIldef wan 44 is a1WayS aSsured. The

end of the TingfofIned piston 40 pToiects beyond the end p1ane of the 11ange caSe 46 and the Specific distance alteration of the elen1ent is Z. The adjacent siInilar diS fance elenlent abuts againSt the end p1ane of the Ting forIned piSfon 40. The end plane of the fing-fofII1ed piston 50, vvhen in feSt, does nof pfoiect beyond the end plane ()f the nange caSe 47, against vvhich the adiacent distanco elon1ent abutS. vvhen the fing-fofIned piston iS puShed out, the specific distance alferation of the e1e ment iS 5. If hydfau1ic 11I1its of the type inuStfafed aTe USed in end to end poSiffon, a cifcu1af infermediafe plate, not i1111Sffated by the deSign, Inust be fixed betWeen then.

In the fofegoing diffefent en1bodinlenfS of the hydTaulic I111ifs vefe dcScfibed. II()W a Ineasufing device accOfd ing to Fig.12 Wi11 be descfibed. In the inuStTated embodfInent it consiStS of a Ineta1 pipe conStituting a suppoffing and guiding nleanS 55. In the pipe thefe iS 0xed a serieS of hydra111ic unitS according to Fig. 3. one end of the pipe is Shut With an end plate 56, Which is provided with a centfa1 threaded aperfure into which an ad justing bo1t and nut 57, 58 afe thTeaded. T,he other end of the pipe is a1So shut With a Screw cap 52. The pipe haS on one Side a 1ongifudina1 S1ot 60 and a diaInetTically oppoSed slot 61. The device has a 1ixed meaSuTing point 62 and a n1ovab1e one 63 Which thfough a device 64 abufting on the pipe is connected With the element SefieS through the s1ot 61. The hydfauHo unitS in their initial po Sition aTe pTeSSed together by a coi1 Spfing 65. T11e hy draulic 11nitS afe fof iI1Stance of fhe character that the e1e menfS 66, 67 oontro1 the measufing fange 0,10.9 the ele mentS 68, 6, the Ineasuring Tange 19 mn1, the elen1entS 70, 71 the mea uTing fange 109o mm and the e1enenf 72 contTols the IneasuTing Tange 300 IT1In. By the -aid of thiS device n1easnfenlontS Within the Whole I nge 3999 mm. can be caffied ont Withfofefva1S of 01 Inm.

The speci0c exact diSfance a]feTafionS afo in thiS caSe 0.1 and 0.1 mm. fo1 the e1ement 00 and 0.2 and 0.S mn1. fof the elen1ent 07. The elenTonts 08, 09 have the SaIfie propoftion In111ti )1ied by 10 and the elelTlentS 70, 71 1ikewiSe multipHed by 100. The olemenf 72haS the Spo cif1c diStance alteration 100 and 200 Tnln., thuS a tota1 of 300 n1Tn. of couTSe anothof pTopoftion between the soalaf nlen1befs in every docado IneaSufe intofva1 than 1:1:2:S, aS nlentioned, iS poSSible, fof instance l=2:3:4.

The oil is condocted to the oleInef1tS 70, 71 and 72 throHgh 11exible pfeSSure ductS aftached to the ipe connoction pieces, xed 10 the TeSpective eleInent and nloving thI1s in the Slot 00 With the distance e1eIT1ent. The eIe InentS 0009 afe arranged in anothef fnanner, Which iS 1if in caSeS Whefe the e1e111ent n10tion is ninute. Tho oil pipeS afe atfaohod to connecting pieceS in the pipe 55. The dl1ctS 73, 74 paSS thfonghfhe pipe vVa]1 to the innof Side of the pipe va1l. TheSe docts vViden in tho displace- Inent difectfon of tho elen1ent and he oi1 dllcts of the o1eInonts are opposite to theIT1 aS the section of the e1e Inent 08 ShoVvS. The connection betveen the inner an(1 tho oXtefiOT oil Supp1y of the elen1ent is preSoTVed in thiS InanneT, vhen the eleInent rnoveS Within itS n1otion1ntervaL The hydraulic unitS afe thus tted as pistonS in the pipe 5 and if oecesSary paoking affangoInentS can bo IIsed, fo1 inSfanco packing fings, Tho pi e 55 InuS be pTovided vvith an outlet 7 for leakagooil aTranged between the e1en1ents. The device can, of co11rSe, be pTovided Wifh changeable n1eaSuring pointS, So that fof inStance the innef pipe diaInetefs oan be nleasufed, of affanged aS a gauge fof fneaSufing the depth of apertuTes.

Tho oi1 Supoly ffom the pfessufe 011 SoUrce to overy diS tance olefnent is Tegulafed by valveS aSSociated With eveTy eleInent, Which Will be deScfibed 1ater on. The va1ve Set vif11 operating buttonS is connected with the dovice to foTIn a unit, Which iS attached to the oil ciTcn1ation SyS- fen1 thfongh an in1et and an outlet doct.

0 hen osing tho ga11ge, the 0adjUSfn1ont is carried oI1t by the ScfeW 57, Fof obtaining for inStance the nea ufo 241% n1If1., the oi1 iS to be conducted thfough the va1ve affangeInent fo one of the disfance elon1entS of the e1e n1ent 71200 nIn1 and fufther to both diStance ele- 1nents of tho elen1ent 70-40 Inn. Then the oi1 iS to be condoofed to one side of the eleI11ent 081 nn. and to both SideS of the eleInent 070.7 InIn.and to one side of the eleInent 000 1 Inn1. In oTdef to get 242 Inn1., the oil iS guided away ffom the elements 00 and 07,fhe Spring 05 pTesSing fhe gauge to 241 n1In., and thon the oi1 iS a1so conducted to the other side of the elen1ent 08, fho nloasofe 242 Inn1. boing thuS obtained. TheSe opera tionS can, of coorSe, be Sin111ltaneoSly caTriod ont.

The devico is not only lin1ited to be a pTeciSion gauge f()1 acoufate oleasofing. Anothef pufpoSe ()f tho invon' 1ion iS to pfoduce a device fof accuTato ad uStIflont of a body in a pTedetefInined position in Tolation to o fixed point. Figs.13 and 14 Show the principles of this offangenont in connecfionvith a Inachine tool the table of v/hich, TeSpectively the woTk piece 0xed on it, iS adiuStable fn Telatiol to the Working too1.

1S Fig. 13 ShovVS, the colun1n of hydrau1ic unit iS af anged in the SaIne Way as in the gauge accofdiogfo Fig,

12. The e1enont3 are thoS 1aced in a pe 70 vhich tightly eovelopS then. The hydrau1ic IInitS 77 82 are of the type accofding 10 Fig. 7, bnt eSPecia11y the eleTneotS 01, 82 can be of the InoInbfane type accordiog to Fig. 8. Tho olen1ents 77, 78 afo of fho type according to 1ig. .3. The oil Supply pipeS of the eleIIents 7790 pfoieot out thfough a 1ongit ldina1 slof 83, vVhi1e tho oi1 Suoply of the elemenfS 81, 82 iS arrangod in the Saine Woy aS that of the elements 0009 in Fig. 12. The pipe 70 i at both ends attached to the SU poTt84. A Zero-adiuStment de vice 85 compoSed of a bo1t and nut and a Stop nt 80 is 11xed fo the one end of the pipe 70. Through a boshfng 87 a puSh fod 00 pTojectS beyond thopioe ond whefo it is attached to a yoke 89. In ofdef to hold the diStance o1enlents c1oSe fo each othef, the Spring 05 iS heTo fo I)laoed by t/o hydra111ic oylindefS 90, 91 vvhich act ol) posite fo the eXpanSioI1 direction of tho diStance elenlentS.

4 The fofa1 effeotive sLlfface of the hydTauHo cylindefS iS of Such a natufo that the oontfacting fofce is a1WayS woakef than the expanSioo fofce of tho distance oleInont The oil pTeS uTo is SuppHed to the oyHndofs fhfougo the oi1 pipeS 92, 93. The piston rods 94, 95 of1he ouxniofy oy1indofS aTe attache(1 to the yoke 09.- The guides, oI1 Which the opefating table SlideSafe 0Xed on the ma ohine tooI bed 84; one of theSe gnidoS 97 can be Seen 111 Fig. 13. The opofating table 90 is connectod with the yoke 89 by aI1 arn1 98. The indicated distance e1enfentS Sefies iS dosignod to contfol the fango 0999.99 n1II1. with intofva1s of 0.01 n1T1. In thiS caSo the speci0c exact diS tance altefationS of the distance elenlen1S aTe also pfo vided vithin oveTy decade intefval in the pfo1)offion 1=1:2:S, Which pfopoftion eX roSSed in Inf11inletTes, TepTesenfS the scalaf IneInbefS of the specific distance alfefationS of the hydTaulic t111it 80. The ooffeSponding scalaT nun1bef for the eleIIlent 79 iS ten tiInes gfeater and fof the eleInents 00, 07 hundfed tiInes gfeatef, Whi1e the sca1af nun1berS for the e1eInents 81 and 82 afe fe Spectively of the Scalaf number fo1 the element 80, if Iflaintaining the iust nlentioned InUtua1 pfopoftion.

Fig. 1S ShowS aS an oxan1p1e an opefating 1)late 99 of the deScribed a(1juStn1ent dovice, AS the co1nInn by hy dfaI11ic onitS iS coInpoSed of tVventy pafticulaf hydrau1ic I1nits, fhe opeTafing plate haS twenty push bUttonS 100, one for every eleInent. Every bl1tton actIlates an oil valve of oustoInary constfuction, aS in an enlafged size iS illlls trated by Fig. 10. Evefy puSh button iS provided with a n1arking of the speci0c distance alteration of the hydraulic unit it iS deSigned to actuate, as ill11stTa ted by 1 ig lS. The oil valve is coInposed of a triple pisfon device 102, 0Xed in the apefture 101 in the opefating p1ate 99. This trip1e piSton arrangeInent is i11ustfated as being in a poSi tion of Test by Tneans of a SpTing 103. Z1n oil duct 104 Conducts oil to the hydfauHc LInit and anothef oi1 docf 105 vith connection doctS to the diffofent va1veS 1eads 10 an oil ollt1ot 107 to an oil SUnp 108. A hydTaulic pI1n1p 109 or a pfeSSnfe n1edil]fI1 accun1111ator, nof illIlstTafed, 1Tain tainS the neceSSafy preSSufe in fhe syStenT. The pfeSSufe oil is conducted into the valve through a duct 110 vifh a connoction dllct 111 betwoon the di1fere1t va1veS. The SySten1 has an oveTPfesSuTo Safety n1eans 112; tho oil is further conducfed to tho ouxiHafy cylindefS 90, 91, of which ono is indicated. vVhen the bLlttof 100 is puShed, the hydraU11c Unit iS connected to the pfesSure Sido of the SySton1 and expandS 1Inti1 it feachos ifs S=peci11c diStance a1te ation. In ofdor to keep the va1ve in thiS poSition, there iS a known indeX1ock arfangement 113 in the valve. 1n ofder fo TetuTn the actuated bllttons, TeSpective1y the valves, in a convenient Way to their norn1al positions, the push bufton 114 is uSed, vvhioh operafeS a hydfau1ic valve. U on I1Shin down the button 114, the reSSufe oil is conducted to t11e 1owof paft of the lower cavity of evefy opera1ing va1ve, Vv11ich oavitios afe connecfed to the gafh ering duct 115. The acfIated o efating buttonS are Te tnrnod, overcoTning the TeSistance of the indeX 1ock af fangen1ont 113, the hydrauHC unifS, which oarliof vere oobjoct to a pfesSure actuation, are connected to fhe oiI Sufnp, and the auxiHary cylinders 90, 91 bring the adiust n1ent deVice back to itS zefo-position, By pushing dovvn o11 opefafing botfons 100, tho lT1aXiIT1llIn diSp1ace1ent of the aduStInent device iS attained, WheToIlpon by hand 1ifting the ap ropTiafe oporating bottons, the deSifed fe (1Llcfionof the Tnaxinun1 displacen1ent iS affained in ofder fo get the corfecf adiostInent.

1t is evident thaf the oPofating pIato can be pfovided with buffonS nunlbered in every button rooV ffon1 1 to 9. ,hen the bufton n1arked, fof inStance, 8 is poShed down, tho valves, Which opefate the hydralllic llnfts vith the nunbers 1, 2, and S, afo octuated siInI1taneouS1y. Especia11y in connection With SUch a devfce, it iS advan tageouS to use e1ectfo-nlagneticaHy operated valves.

AS an eXaInple of one of the Tlany colnbination pos sioilifieS Fig. 17 Shows s1Ic11 a dovice dividod into v() SepaTofe partS which actoate the opefating tab1e of a nTa- Chino tool. The Inachine bed 110 is on1y indicated in ofdeT to Tnafk tho Supports of the device. A distance adiustTnent device 117 is HXed fo tho bed and is oon1DoSed of a colomn of hydraUHc LInits, vvhich covef, for insfance, the fange 0.010.99. The oi1 ductS 118 are fiXed to the caSe of the diStance adiflstInent device 117. AnotheT dfS tance adjnStnont device 119 iS in itstofa1novabIe in aXia1 direction aS also its paTicU1ar hydrau1ic unitS in Telation to the case. IfS fange is fof inStance 1999 InTI1. The oi1 Conducts 120 are f1eXible. In ofdor to got, When neceS- Sary, tho effect of both deviceS 117 and 119 added together, a leyer having two aTn1S 121 is uSed, one arIn of which in the iHustrated case iS twodmes aS 1ong aS the other. In both ends it haS Suitable e1eInents 122, 123 aS fof in Ineans and S1idably n1ounted thefein, tWo annulaf pistonS oach piSton S1idably Inounted 011 one Side of Said tTans versely extending vva11 Inen1beT and defini11g vvit11 the Sanle a chan1ber coInInunicating vvith one of Said con dnits, and tWo annulaT Stop lT1eInbeTS Inonted on said ffanSveTSely extending Wa11 n1en1bef, each of said stop IneInbers passing through one of said annular piStonS and having a Iadial pfoiection liII1iting movement of the aSsociated piSton; a Second set of hydTaulic unitS Inountod in the interior of Said guide lTleans end to end, each unit of said second Set including one cylindeT n1eanS foTIned vvith a conduit having one end on the inneT SUT- face, and the other end on the outef SuTface of Said cy1 indef D1eans; tTanSverSa1 cloSufe Ineans closing one end of Said cylindef lneans; at least one piston IneanS Inount ed in said cylinder Ineans Inovably in axial direction betvveen tWo poSitions, and at least in one of Said tvvo positionS pTojecting out of the other end of Said cylinder IIleanS, Said piSton nleans defining in said cylinder nleans t()gethef With Said tTanSvefSa1 c1osuTe IneanS a Chan1ber communicating With Said one end of said conduit; a

Stop nleInbef engaging said piston nleanS in said one pfo-- jecting poSition, each of Said hydfau1ic units being 1on gitudinany eXpandable betvveon tWo pfedeterInined 1in1 its froIn a compTesSed condition to an expanded condi tion, and conlpresSible fToII1 an expanded condition to a compfeSSed condition, there being gfoupS of hydfaulic unitS provided, each of said gfoupS of hydraulic units conSiSting of hydraulic units having a diffeTence iI11ength in expanded and compTeSSed condition i11 the fange of a different denon1inationa1 ofdef of a lTleaSUTe of length, Said hydraulic unitS conStituting a 1ongitudinany eX- pandable and con1pfeSSible coluInn having a length vari able betweontvo pfedetern1ined lilT1itS adiIlstable stop nleanS fI1oI1nted on Said suppoTting nleanS at one end of Said olongated guiding IneanS engaging one end of Said expandable and coInpfessiblo colunln; an actuated IT1on1- ber engaging the otheT end of said coluInn and Inounted on Said Suppofting nleans II1ovably between tWo poSitions coffesponding to the longitudina1 extenSion of said co1- uInn in expanded and in compreSSed condition of Said hydTaulic units; a set of 11uid SUpply IneanS SUpplying an aotuating nuid through one of said conduitS Separately to eac11rchan1ber of Said hydraulic unitS for eXpanding the safne; hydTau1ic preSSUre n1eans abutting at one ond thefeof againSt Said suppofting n1eans and at the other end theTeof againSt Said otheT end of said colun1n and fofcing Said hydraulic UnitS fron1 expanded to coInpTeSSed oondition; a furfhef f111id Supp1y neanS fof actu ating Said hydTouHo pTesSIlTe ITleanS; and opefafing Ineans for Separafely actuating each of Said f111id supply Ineans.

7, A IneaSuring and actuating device conTPriSing, in coInbination, Supporting Ineans if1c111ding elongafed tubu 1al guiding Ineans fofmed vvith a plufality of fadial con duits; a Set of hydraulic units n1onted in the iI1terior of Said guiding nleanS end to end, at leaSt tvvo of Said hydfaulic IlnifS including an annular Wall IfleInbeT tranS- vefSe1y extending throI1gh said tubulaf guiding nleanS and sIidably mounted theTein, tvvo annulaT piStons each piSton slidably nloUnted on one side of Said tranSvefsely eXtending Wal1 n1enlbef and donning With the SaIIle a chaInber, coHapSible and expandable containef IneanS located in at least one chaInbef and coInInunicating With one of Said conduits, and two annulaT Stop Inen1 berS n1ounted on Said tranSversoly extending wan Inefnber, each of said stop InoInbefS pasSing throngh one of said annulaT piStons' and having a Tadial pTojection liIniting Inovefnent of the associated piston, each of Said hydraulic 11I1its being longitudinally expandable between tvvo pTedeteTInined liInits ffoII1 a coInpressed condition to an eXpanded condition, and coInpTessible ffoII1 an eXpanded condition to a conlpresSed condition, thefe being groups of hydraulic unitS provided, each of said grou S of hydraulic unitS consiSting of hydraulic units having a difference in length in eXpanded and coInpreSSed condition in the range of a diffefent denoIninational order of a IneaSure of length, Said hydTau1ic unitS c()I1Stitl1ting a longitudinaHy expandable and compTeSSible coluInn having a length vaTiable botvveen tvvo predetefInined liInits; adjustable Stop n1eans n1ounted on Said Support ing fneans at one end of Sai(1 e1ongated guiding IneanS engaging one ond of Said eXpandab1e and compreSSible colunln; an actuatod IneII1ber engaging the other end of Said co1urIIn and Inounted on Said SUppoTting IneanS nlovably betvveen tvvo positionS cofresponding to the longitudinal extension of Said. colun1n in expanded and in con1pTesSed condition of Said hydfaUlic units; a Set of f111id supply Ineans supplying an actuating uid through.

one of Said conduitS Separately to each chaInbef of Said hydfauHc units for expanding the saIne; hydrauHo pfeS SuTe nleans abutting at one end theTeof againSt said SUp pofting IneanS and at the other end thereof againSt Said othof end of Said Co1umn and fofcing said hydrauHo units froIn expanded to coInpTessed condition; a further f111id SupPly IneanS for actuating said hydrauHc pfeSSuTe Ineans; and opefating meanS for sepaTately actuating each of Said ffI1id Supply Ineans,

- 1eferenceS (:ifed in tho file of thiS patent UNITED STATES PATENTS 691,69Z zvvoigbergk 1an. 2.1 1902 1,S61,34Z MaTtin Nov. 10, 19Z5 1,684,033 1osephS, I1 Sept. 11, 1928 Z 197,867 K1ement Apr. Z3 1940 FOREIGN PATENTS Z43 6Z0 SWitzefland 1an. 16, 1947 

